I am using kde-3.4. I cannot say that there are any huge differences or apparent improvements, from a user's perspective. They have integrated amarok into the konqueror sidebar, for one (not that I ever use that - better just to open amarok and have a clean display when I want to listen to music, and have konqueror free to do other things). I imagine it must be primarily a bug-fix issue, but there weren't any bugs I had come across, that I recall.
The huge gains (laud! laud!) came when I switched from the standard fedora kde to the kde-redhat project version of 3.4. Wow! For the first time since the ol' redhat daze, the system works like it's supposed to. Click on a file and there's music, instead of noatun hanging up and kaboodle jamming. There's video, so you can watch mpg movies and rent dvds and not have to use windows. What's an option to windows worth if you can't use it for all your needs? I don't need windows and don't use it at all, but only because everything works in Linux. There are lots of little things like this - I can't remember them all - everything just works, all of it! I can't say it enough. It's so good, for the first time in years, I'm tempted not to upgrade to FC4 (yes, I know I'm dreaming, of course I will upgrade, and on the first day possible, but not until kde-redhat is ready).
Thank you - this is some meat! I presume I can search on KDE-redhat and find this iteration?
-- Claude Jones Bluemont, VA, USA